FIG. 1 shows an example of an environmental control system 100 generally of the type described, for example, in U.S. Pat. Nos. 5,016,003 and 5,345,226. System 100 is a versatile, responsive switch-activated environmental control system that allows users to control their environment, for example, turning on lights and appliances, changing television stations, adjusting volume levels, using a telephone, recording messages, calling a nurse or attendant, or controlling a hospital bed. For example, system 100 may include a main unit 102 that preferably is microprocessor-based and software-controlled. Main unit 102 interfaces with a user 104 through a user control switch 106 and a back lit display 108. In addition, main unit 102 may include a speech synthesizer that allows the system 100 to talk to user 104 through headphones 110, speakers, etc. User control switch 106 may be a conventional type of "dual action" switch normally controlled by a severely disabled person, e.g., a two-position switch such as a "sip and puff" switch, a tongue switch, a rocker switch, or a dual head switch activated by slight left/right head motion. Such switches often provide a single-pole-double-throw (SPDT) set of switch contacts (this same switching action can also be effected by a pair of normally open SPST switches) for three distinct, mutually-exclusive switch positions (e.g., contact set one closed, contact set two closed, or both contact sets open) corresponding to the physical state of a user relay-controlled actuator (e.g., "sip," "puff," and not activated). See FIG. 2A. Many severely disabled individuals cannot control a more complex switch or user control interface such as those found on typical home appliances and equipment. Therefore, all user control operations and functions performed by system 100 are capable of being actuated and controlled using only such a 3-state "dual action" user control switch 106.
In the system 100 shown in FIG. 1, a user-friendly "menu-driven" menu structure provides control in response to the user control switch 106. Display 108 may display a sequence of menu options to the user 104, and a speech synthesizer internal to main unit 102 may generate corresponding audible menu prompts to guide the user. The menu prompts may be nested to whatever level is desired. Such displayed and/or audible menus allow user 104 to access an almost unlimited variety of different control functions using only a dual action user control switch 106.
For example, the user may control telephone electronics internal to main unit 102 and connected to a telephone line/jack 112. The user may optionally control a tape recorder 114 to dictate, play back or both. The user 104 may speak into a user microphone 116 to interface with the telephone electronics and/or tape recorder 114, and can hear telephone and tape recorder audio through speaker 111 and/or headphones 110 and/or internal speaker within 102. User 104 may also, through main unit 102 and its menu-driven user interface, actuate conventional home entertainment appliances such as a television set 118, a compact disc player 120, a stereo receiver 122, and/or a video cassette recorder 124 via an infrared (IR) remote control link 126 driven by main unit 102. User 104 may also control 110 VAC operated electric appliances (e.g., a lamp 128, a fan 130, etc.) via a conventional X-10 power line interface 132 which may inject signals into house wiring to control remotely located/operated conventional X-10 switching modules 134A, 134B. User 104 may also actuate relay-controlled switch contacts within main unit 102 to interface with other systems and appliances such as, for example, hospital lights 136, a nurse call button 138, controls of an electrically-operated hospital bed 140, etc.
The array of control interfaces provided by main unit 102 is very flexible for control of a wide variety of equipment and appliances. Moreover, despite such versatility of environmental control system 100, further improvements are possible.
In particular, severely disabled users 104 may, in some cases, want to control more than just one system designed to interface and be operated by a dual action user control switch 106. For example, some users may wish to control an environmental control system 100 such as is shown in FIG. 1, and also control an additional system such as, for example, "augmentative communication device" ("ACD"). An ACD permits a non-verbal user, through switch control, to invent/construct phrases and sentences and then communicate them either via printed page or via voice synthesizer. A severely disabled person normally controls an ACD using a dual action user control switch. In many instances, however, it is impractical or impossible for a user to use, operate, or reach more than a single user control switch 106.
For example, users with limited head motion may be unable to select between the straw end of two different "sip and puff" switches. In the case of a tongue switch, it is most times impossible for a user to operate a pair of co-located dual action switches. Rocker switches are often used by people who have control of one (and only one) hand or finger; it may be impossible for such users to reach, much less control, more than one rocker switch. Severely disabled users cannot operate more than one pair of minimum deflection head switches since they typically lack head control to move their head or other extremity in more than one unique back-and-forth trajectory.
Even if a particular disabled user could operate more than one user control switch 106, there are disadvantages to providing or requiring a second user control switch. For example, a second switch may be too expensive. A good quality sip and puff switch, including extension cable, adaptor (if required), mechanical mounting hardware and custom installation, could cost in excess of $300.00 at today's prices. Another "expense," which may be more serious than simply monetary, is the space cost for placement of a second switch. If a severely disabled person is using a respirator and an environmental control system 100 and display 108 mounted on a gooseneck, there usually is no space to mount another switch. In fact, the user's immediate area is typically 100% utilized and frequently gets disturbed due to need for fast accessibility by personal care attendants, family members and nurses in administering oral medicine, giving IV medication, and performing personal care activities. A second user control switch for a severely disabled individual requiring this level of care is usually impractical to consider.
In the past, users sometimes solve the problem of trying to operate two different systems with the same user control switch 106 by having an attendant unplug the switch from one unit and plug it into the other unit as required. For example, a severely disabled person might have an attendant disconnect the user control switch 106 from environmental control system main unit 102 and connect it instead to an ACD when the user wants to communicate using the ACD. Later, when the user finishes a particular communications task using the ACD, the user may then ask the attendant to disconnect the ACD and reconnect the environmental control system 100 so the user can control their environment. This manual plugging and unplugging of a user control switch is highly inconvenient, however, since the user may require the capabilities of both types of equipment simultaneously. What the severely disabled user really wants is to be as independent as possible and therefore in "real time," decide for himself/herself which system functions to control.
The present invention provides a solution to this problem. In accordance with one aspect of the present invention, an environmental control system 100 is improved to include an auxiliary control interface. The auxiliary control interface, which may be operated under control of a microprocessor responsive to the user control switch 106, appears electrically, from the "viewpoint" of a further controlled system or device connected to the auxiliary control interface, to be electrically the "same" or "equivalent" to the manually-actuated contacts of user control switch 106. When the user wants to operate the auxiliary control interface, he/she operates the user control switch 106 in accordance with special menu-driven selections, to place environmental control system 100 into a special "pass through" mode. When operating in this special mode, the environmental control system 100 responds to closures of user control switch 106 by closing electronically controlled switching circuits that electrically "look like" user control switch 106. Main unit 102 detects the switch closures provided by the user through user control switch 106, and responds to those switch closures by, for example, electrically operating a pair of SPST relays so that the relay switch closures "mimic" or "emulate" the switch closures provided by user control switch 106. In this way, the auxiliary control interface interfaces to another existing disability system or device by emulating the electrical switching action of a conventional, mechanically-actuated user control switch 106 operated by the user. For example, the auxiliary control interface may provide the electrical and functional equivalent of a "sip" and "puff" switch interface to an existing appliance in response to microprocessor control based on user actuated "sip" and "puff" switch inputs.
In accordance with another aspect of the present invention, the mimicry or "emulation" provided by the auxiliary control interface is intentionally made imperfect to provide a means by which the user may control the environmental control system 100 to cease operating in the special "pass through" mode. Generally, the user has only the user control switch 106 by which he must control all aspects of the operation of the environmental control system 100 and any other system or device attached to and controlled by the auxiliary control interface. In accordance with this further aspect provided by the present invention, once the environmental control system 100 is operating within the special "pass through" mode, it continually monitors certain user input switching characteristics to determine whether it should cease operating in the "pass through" mode and begin operating in "normal" mode to permit the user to control devices in his environment such as TV 118, tape recorder 114, etc. For example, the main unit 102 may time how long the user provides a manually actuated closure of user control switch 106 whenever environmental control system 100 is operating in the "pass through" mode. If the amount of time matches certain preset time parameters (e.g., longer than a certain amount of time), main unit 102 may sense this and cause system 100 to cease operating in the "pass through" mode and to instead begin operating in the "normal" mode.
In accordance with another aspect provided by the present invention, environmental control system 100 may optionally immediately switch from the special "pass through" mode to the "normal" mode upon the occurrence of some event other than user actuation of switch 106 (e.g., detecting that the telephone has begun ringing) to allow the user the convenience of automatically changing back to a "normal" mode of operation (e.g., to permit the user to conveniently answer the telephone without manually telling the system 100 to cease operating in the "pass through" mode).